A SaaS application uses two redundant 10 Gbps Direct Connect links to a colocation and must start encrypting traffic between AWS and the colocation edge routers while keeping the same bandwidth. The colocation already has encryption to the on-prem network. The company wants the solution with the least operational overhead. What should a network engineer do?

The correct answer is to deploy new 10 Gbps Direct Connect connections with MACsec. MACsec (Media Access Control Security) provides encryption at Layer 2, directly on the Direct Connect link itself, maintaining the full 10 Gbps bandwidth. This is the most efficient solution for encrypting traffic over Direct Connect without significant performance degradation or complex overlay networks, and it has the least operational overhead as it's a direct link encryption. Option A is incorrect because a public VIF with encryption typically implies IPsec VPN over the public internet or a public VIF, which would likely not sustain 10 Gbps bandwidth due to IPsec overhead and potential internet latency. Option B is incorrect because Site-to-Site VPNs over a private VIF (or any VPN) introduce IPsec overhead, which would reduce the effective bandwidth below the required 10 Gbps. Option D is incorrect because deploying Site-to-Site VPNs on top of MACsec-enabled Direct Connect connections is redundant and introduces unnecessary overhead, again likely preventing the achievement of the full 10 Gbps throughput. MACsec alone provides the required encryption at the desired bandwidth.